diff options
Diffstat (limited to 'lib/libthr/thread/thr_suspend_np.c')
| -rw-r--r-- | lib/libthr/thread/thr_suspend_np.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/lib/libthr/thread/thr_suspend_np.c b/lib/libthr/thread/thr_suspend_np.c new file mode 100644 index 0000000..d5868e8 --- /dev/null +++ b/lib/libthr/thread/thr_suspend_np.c @@ -0,0 +1,144 @@ +/* + * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include "namespace.h" +#include <errno.h> +#include <pthread.h> +#include <pthread_np.h> +#include "un-namespace.h" + +#include "thr_private.h" + +static int suspend_common(struct pthread *, struct pthread *, + int); + +__weak_reference(_pthread_suspend_np, pthread_suspend_np); +__weak_reference(_pthread_suspend_all_np, pthread_suspend_all_np); + +/* Suspend a thread: */ +int +_pthread_suspend_np(pthread_t thread) +{ + struct pthread *curthread = _get_curthread(); + int ret; + + /* Suspending the current thread doesn't make sense. */ + if (thread == _get_curthread()) + ret = EDEADLK; + + /* Add a reference to the thread: */ + else if ((ret = _thr_ref_add(curthread, thread, /*include dead*/0)) + == 0) { + /* Lock the threads scheduling queue: */ + THR_THREAD_LOCK(curthread, thread); + suspend_common(curthread, thread, 1); + /* Unlock the threads scheduling queue: */ + THR_THREAD_UNLOCK(curthread, thread); + + /* Don't forget to remove the reference: */ + _thr_ref_delete(curthread, thread); + } + return (ret); +} + +void +_pthread_suspend_all_np(void) +{ + struct pthread *curthread = _get_curthread(); + struct pthread *thread; + int ret; + + THREAD_LIST_RDLOCK(curthread); + + TAILQ_FOREACH(thread, &_thread_list, tle) { + if (thread != curthread) { + THR_THREAD_LOCK(curthread, thread); + if (thread->state != PS_DEAD && + !(thread->flags & THR_FLAGS_SUSPENDED)) + thread->flags |= THR_FLAGS_NEED_SUSPEND; + THR_THREAD_UNLOCK(curthread, thread); + } + } + thr_kill(-1, SIGCANCEL); + +restart: + TAILQ_FOREACH(thread, &_thread_list, tle) { + if (thread != curthread) { + /* First try to suspend the thread without waiting */ + THR_THREAD_LOCK(curthread, thread); + ret = suspend_common(curthread, thread, 0); + if (ret == 0) { + THREAD_LIST_UNLOCK(curthread); + /* Can not suspend, try to wait */ + THR_REF_ADD(curthread, thread); + suspend_common(curthread, thread, 1); + THR_REF_DEL(curthread, thread); + _thr_try_gc(curthread, thread); + /* thread lock released */ + + THREAD_LIST_RDLOCK(curthread); + /* + * Because we were blocked, things may have + * been changed, we have to restart the + * process. + */ + goto restart; + } + THR_THREAD_UNLOCK(curthread, thread); + } + } + + THREAD_LIST_UNLOCK(curthread); +} + +static int +suspend_common(struct pthread *curthread, struct pthread *thread, + int waitok) +{ + long tmp; + + while (thread->state != PS_DEAD && + !(thread->flags & THR_FLAGS_SUSPENDED)) { + thread->flags |= THR_FLAGS_NEED_SUSPEND; + tmp = thread->cycle; + _thr_send_sig(thread, SIGCANCEL); + THR_THREAD_UNLOCK(curthread, thread); + if (waitok) { + _thr_umtx_wait_uint(&thread->cycle, tmp, NULL, 0); + THR_THREAD_LOCK(curthread, thread); + } else { + THR_THREAD_LOCK(curthread, thread); + return (0); + } + } + + return (1); +} |
